FEATURES Footswitch toggles amp on/bypass Red LED indicates "on" Gain knob adjusts total output volume when micro amp is engaged Rugged, compact metal enclosure *Powered by a single 9-volt battery or Dunlop ECB-003 AC Adapter (both sold separately) DESCRIPTION The MXR M-133 Micro Amplifier Pedal adds a preset amount of gain, using a single control!With a guitar, this lets you boost your signal for lead work, adjust between 2 different guitars with unmatched output (i.e., humbucker to single coils), or it can supply a permanent boost in a long effects chain where signal drop-off is a problem. SPECIFICATIONS Boosts signal with a preset amount of gain up to +26dB Dimensions (Overall): 2.6 inches (H) x 4.4 inches (W) x 5.5 inches (D) Weight: 1.1 pounds *Powered by a single 9-volt battery or Dunlop ECB-003 AC Adapter (both sold separately)Model# M133